RuggedCom RS400 manual Problem Eight, Problem Nine

Spanning Tree

If the controller fails around the time of a link outage then there is the remote possibility that frame disordering or duplication may be the cause of the problem. Try setting the root port of the failing controller’s bridge to STP.

Problem Eight

My network runs fine with your switch but I occasionally lose polls to my devices.

Inspect network statistics to determine whether the root bridge is receiving TCNs around the time of observed frame loss. It may be possible that you have problems with intermittent links in your network.

Problem Nine

I’m getting a lot of TCNs at the root, where are they coming from?

Examine the RSTP port statistics to determine the port from which the TCNs are arriving. Sign- on to the switch at the other end of the link attached to that port. Repeat this step until the switch generating the TCNs is found (i.e. the switch that is itself not receiving a large number of TCNs). Determine the problem at that switch.

ROS™ v3.5 168 RS400